Phosphorus flame retardant compositions

ABSTRACT

The present invention relates to phosphorus-containing compositions which are polymeric esters having flame retardant properties and also a process for the production thereof, as well as the combinations of such phosphorus compositions with otherwise combustible base materials exemplified by various organic polymers, for example polyamides or polyesters.

BACKGROUND OF THE INVENTION

The present invention relates to flame retardant compositions which arephosphorus-containing esters, and which are particularly adapted toprevent crystallization and exuding or oiling out when thesecompositions are employed in organic polymers. Esters of various typeshave been employed as flame retardant components of various polymers.However, a common difficulty when using such esters has been theincompatibility of the ester with the organic polymer base material, forexample, polyamides such as nylon, for example nylon 6,6. The additiveesters have sometimes crystallized after a period of time, or have beenexuded out of the polymer so that the desired flame-retardant modifyingeffect on the organic polymer was lost.

The present polymeric esters are ternary compounds which are formed fromalcohol components and phosphorus-containing acid halides, esters oramides. The polymeric esters have at least three of the alcohol andphosphorus moieties in the product. Control of the relative proportionsof the alcohol and of the phosphorus moieties as well as the relativemolecular weight of the starting materials and of the final polymericesters makes it possible to obtain products having properties ofsolubility, melting point and crystallization temperature to provideflame retardant properties and other physical properties without thedifficulties of exuding or crystallization.

SUMMARY OF THE INVENTION

In accordance with the present invention a process of esterification isemployed to form new phosphorus esters having a total of at least threedifferent alcohol and phosphorus-containing moieties: (A) an aliphaticalcoholic moiety of an alcoholic reactant of 5 to 20 carbon atoms, andhaving from 2 to 10 hydroxyl functional groups, preferably from 2 to 6,with the proviso that there is no hydrogen atom on the carbons which arebeta to the hydroxyl oxygen, (B) a moiety of a phosphorus-containingacid halide, ester or amide reactant of 0 to 20 carbon atoms, and havingfrom 1 to 4 functional groups selected from the group consisting ofhalogen, ester, (-OR) and amide (-NR₂) groups where R is an aliphaticradical of 1 to 6 carbon atoms, and (C) a different alcoholic moiety asdefined in (A) or a different phosphorus-containing moiety as defined in(B), the said ester having a degree of aggregation of 2 to 100.

The table below shows typical alcohol and phosphorus moieties fromrepresentative reactants. The esterifiable groups described above arebonded at the valences shown for the respective compounds.

    __________________________________________________________________________    Aliphatic Alcohol Component (A)    OCH.sub.2C(CH.sub.3).sub.2CH.sub.2 O                          2-functional                          (e.g. neopentyl glycol moiety)     ##STR1##             3-functional (e.g. trimethylolethane moiety)     ##STR2##             4-functional (e.g. pentaerythritolmoiety)     ##STR3##             (6-functional) -  (e.g. dipentaerythritol moiety;                          and higher                          oligomeric forms such as polypentaerythritol,                          also containing the tri and tetra forms).    Phosphorus Component (B)    R.sub.2 P(O)          mono-functional                          (e.g. dimethylphosphinyl moiety)     ##STR4##             2-functional (e.g. chloromethylphosphonyl moiety)     ##STR5##             3-functional (e.g. phosphoryl moiety)     ##STR6##             4-functional (e.g. bis(phosphonyl) methane moiety)    R.sub. 2 P            mono-functional                          (e.g. diphenylphosphino moiety)    RP                    2-functional                          (e.g. methylphosphinidene moiety)     ##STR7##             3-functional                          (e.g. phosphinidyne moiety)    __________________________________________________________________________

Each of (A), (B) and (C) are present at from 1 mole % to 99 mole %, withthe proviso that the number of alcoholic groups on the alcoholicreactants is equal to the number of the said functional groups on thephosphorus-containing reactants.

The aliphatic alcohol component of the polyesters is characterized bythe absence of hydrogen atoms on the β-carbon atoms (relative to thehydroxyl groups). This has been found to result in products which are"elimination stabilized" so that the esters do not decompose readilyupon heating. Products not so characterized, upon heating, form olefinsand acids of phosphorus which latter acids break down and degradeorganic polymers with which such ester products have been admixed forflame retardancy.

The alcohol and the phosphorus-containing compounds may be substitutedby halogens such as bromine or chlorine. The phosphorus-containingcompounds may also be employed as the sulfur analogues, e.g. PSCl₃instead of POCl₃.

A representative polymeric structure is shown below, based upon thereaction of CH₃ C(CH₂ OH)₃, C₆ H₅ POCl₂ and OPCl₃. ##STR8##

The process for the preparation of the present ternary esters isconducted in the temperature range of 50° to 250° C. Control of theproportions of the (A), (B) and (C) components permits controlling thephysical properties of the product. A solvent is not essential, but anon-reactive solvent such as benzene, toluene, octane, or decaline maybe employed. The use of a catalyst is also optional; if desiredmagnesium chloride or an organic base, e.g. piperidine, pyridine,piperazine, or picoline accelerate the rate of reaction.

The products of the present invention are useful as flame retardants forotherwise combustible organic polymers. For this purpose the estercompounds may be applied as a solution to shaped or formed polymericobjects such as films, fibers, extruded and foamed products utilizing asolvent system such as alcohol, e.g. ethanol, or acid amides such asdimethylformamide. The esters can also be admixed with the moltenorganic polymer or a solution of such polymers in a solvent, beforeextrusion from spinnerettes to form fibers.

The invention also includes the combination of an organic polymer suchas a polyester or a polyamide together with the abovephosphorus-containing polymeric ester. The invention also includescopolymers such as block copolymers of the above organic polymerstogether with the present polymeric esters, such as are obtained byester interchange. The end groups can be an hydroxyl group or a halogen.However the terminal phosphorus may have groups permitting esterinterchange, and interpolymer formation with the organic polymer such aspolyethylene terephthalate.

The compounds of the present invention are useful in fire-retardantmaterials. The method of testing fire-retardant properties is A.S.T.M.Designation D 2863-70, entitled "Standard Method of Test forFlammability of Plastics Using the Oxygen Index Method."

In the Oxygen Index (OI) testing procedure the relative flammability ofa plastic material such as nylon, or polyethylene terephthalate isdetermined by measuring the minimum concentration of oxygen in a slowlyrising mixture of oxygen and nitrogen that will just support combustion.Consequently the oxygen index expresses such minimum concentration ofoxygen, expressed as volume percent, in a mixture of oxygen and nitrogenthat will just support combustion.

The test is conducted by burning the material in a test column which isa heat resistant glass tube of 75mm minimum inside diameter and 450 mmminimum height. At the bottom of the tube is a bed of glass beads about100mm deep to mix and distribute the gas mixture. Within the glass tubeused as the test column there is a specimen holder to support thetreated plastic material, while the apparatus is supplied with oxygenand nitrogen flow and control devices. The apparatus is also providedwith an igniter which is a separate tube through which a combustible gassuch as natural gas is used to ignite the test specimen. In the presenttesting program glass scrim supported molded sheets of nylon orpolyethylene terephthalate ca. 0.2mm thick and about 25mm by 100mm insize are used as the test specimens which are prepared from nylon orpolyethylene terephthalate powder and 1% to 20% by weight of the fireretardant additive; the data in the present work correspond to about 10%relative to the total mixture. Upon molding of the organic polymer,e.g., nylon or polyethylene terephthalate, and the additive, an intimateadmixture or melt of the molecules of the components is obtained.

In conducting the test, the specimen is clamped in the holder in thetest column after which the desired initial concentration of oxygen isintroduced to the ignited specimen. A number of tests are conducted todetermine the minimum concentration of oxygen that will just supportcombustion.

The present polymeric esters are useful in combination with organicpolymers or resins generally to reduce combustibility. The normallyflammable organic polymers which are rendered flame retardant inaccordance with the invention may be natural or synthetic but arepreferably a solid synthetic polymer, more preferably a nylon or estertype polymer. Examples of the polymer are cotton, wool, silk, paper,natural rubber, and paint, and also the high molecular weighthomopolymers and copolymers of amides, e.g., (nylon 66 and nylon 6).Other polymers include esters such as polyethylene terephthalate; andpolymers of other unsaturated aliphatic and aromatic hydrocarbons, e.g.,ethylene, propylene, butylene, styrene, etc.; and also acrylic polymers,e.g., polyacrylonitrile, polymethyl methacrylate, alkyd resins, as wellas cellulose derivatives, e.g., cellulose acetate, methyl cellulose,etc. Still other polymers include epoxy resins, furan resins, isocyanateresins such as polyurethanes, melamine resins, vinyl resins such aspolyvinyl acetate and polyvinyl chloride, resorcinol resins, syntheticrubbers such as polyisoprene, polybutadiene-acrylonitrile copolymers,butadiene-stryrene polymers, butyl rubber, neoprene rubber, ABS resinsand mixtures thereof. Since the compositions of the invention areunusually effective flame retardants they are normally combined in flameretarding proportions with the organic polymer at relatively lowconcentrations, e.g., about 1-20 wt.%, preferably about 3-15% based onthe weight of the total mixture. The additive is incorporated byphysical mixing, by milling, or by impregnation, e.g., from a water oralcohol dispersion or solution, or by dissolving or dispersing in themolten polymer before extrusion such as in the form of fibers or sheets.It should be noted that it is within the scope of the invention toincorporate such ingredients as dyes, pigments, stabilizers,antioxidants, antistatic agents and the like into the novelcompositions.

The following examples are illustrative of the invention but are notlimitative of the claims of the present patent application.

EXAMPLE 1

The use of dipentaerythritol as the alcohol component is shown in thepresent example, while the phosphorus components are phosphorusoxychloride and chloromethylphosphonic dichloride. The chemical reactionvessel is charged with 25.9 grams of dipentaerythritol (0.1 mole). Thisreactant is slurried into 250 ml of toluene and heated to reflux whilestirring under a nitrogen atmosphere. The phosphorus components, 0.1mole of POCl₃ and 0.15 mole ClCH₂ POCl₂, in the respective amount of15.4 grams and 25.1 grams are added slowly to the reaction mixture inthe presence of 0.5 grams of pyridine as a catalyst. The reactiontemperature is about 80° C for a period of 24 hours, after which theprecipitated polymeric ester is removed by filtration and washed withtoluene, followed by drying at 100° C under vacuum. The ester does notsupport combustion, is insoluble in water, chloroform, dimethylformamideand toluene.

The present ester has the formula

    { P(O)! (ClCH.sub.2 P(O)!.sub.1.5  OCH.sub.2).sub.3 CH.sub.2 OCH.sub.2 (CH.sub.2 O).sub.3 !}.sub.n

where n is about 20. The polymer does not support combustion andimproves the flame retardancy of organic polymers such as nylon. The useof this product as a flame retardant improves the flame retardancy ofpolyethylene terephthalate.

EXAMPLE 2

The present example employs trimethylol ethane and pentaerythritol asalcoholic moieties with phosphorus oxychloride according to the equationshown below to prepare an ester:

    ______________________________________     ##STR9##    MW 254      MW 136.2      MW 153.4    0.1 moles   0.1 moles     0.23moles    25.4 gms.   30.6 gms.     35.8 gms.    1/n{ CH.sub.3 C(CH.sub.2 O).sub.3 ! C(CH.sub.2 O).sub.4 ! P(O)!.sub.21/3    }.sub.n    ______________________________________

A chemical reaction vessel is charged with the above components,together with 0.5 grams of magnesium chloride as a catalyst, and 250 mlof toluene as a solvent. The reaction is conducted at about 110° C for aperiod of 3 hours with the dropwise addition of the phosphorusoxychloride. Further heating is continued until evolution of hydrogenchloride diminishes, and the supernatent liquid gives a negative testfor chloride. A white product is removed by filtration and is thenwashed with toluene to obtain a white powder as a 100% yield of theester, which begins melting at about 240° C.

The ester, with n about 5 as the degree of aggregation, does not supportcombustion and is useful as a flame retardant component withpolyurethanes.

EXAMPLE 3

The production of a three-component phosphorus-containing ester from twodifferent alcoholic components, namely pentaerythritol andneopentylglycol and using phosphorus oxychloride as the phosphoruscomponent is carried out in accordance with the equation shown below:

    ______________________________________     ##STR10##    MW       136.15       104.15     153.4    gms      20.42        10.42      40.9    moles    0.15         0.1        0.266    1/n{ C(CH.sub.2 O).sub.4 !.sub.0.75  (CH.sub.3).sub.2 C(CH.sub.2 O).sub.2    !.sub.0.5  P(O)!.sub.1.33 }.sub.n    ______________________________________

The two alcoholic components are charged to a reaction vessel togetherwith 250 ml of toluene and 0.5 grams of pyridine. The reaction mixtureis brought to reflux temperature at about 110° C and the phosphorusoxychloride diluted to 250 ml with toluene is slowly added. After a 3hour reaction period, the supernatant liquid is checked as being free ofchlorine and hydrogen chloride evolution is completed. The product isremoved from the reactor and dried in a desiccator giving a productwhich is composed of colorless hard crystals softening at 60° C. The useof the above product in the flame retardancy test gives an Oxygen Indexof 25 with polyethylene terephthalate as the organic polymer (a controltest without additive is about 19 O.I.)

EXAMPLE 4

The use of two different phosphorus-containing components is shown inthe present example which proceeds according to the equation below:

    ______________________________________     ##STR11##    MW       136.15       153.4      1.33    moles    0.24         0.04       0.42    gms      32.68        6.13       55.86    1/n{ C(CH.sub.2 O).sub.4 ! P(O)!.sub.0.17  CH.sub.3 P(O)!.sub.1.75    ______________________________________    }.sub.n

The pentaerythritol is charged into a reaction kettle together with 250ml of toluene and 0.5 grams of piperidine. After the mixture is heatedto refluxing temperature at about 110° C the two phosphorus componentsare slowly added in a solution of 250 ml of toluene. The heating iscontinued until HCl evolution diminishes and the supernatent liquidshows only a trace of chlorine. The crystalline product is removed byfiltration and washed with toluene and subsequently dried under vacuum.The product has an initial melting point of 85° C.

The above phosphorus ester when employed in a flame retardancy testgives an Oxygen Index of 23 when employed to the extent of 10% by wt. ofthe total composition in polyethylene terephthalate.

EXAMPLE 5

Using the procedure of Example 1, but with the use of differentproportions of the reactants of the previous example the reaction isconducted according to the equation below:

    ______________________________________     ##STR12##    MW       136.15       153.4      133    moles    0.21         0.07       0.315    gms      28.59        10.74      41.90    1/n{ C(CH.sub.2 O).sub.4 ! P(O)!.sub.0.33  CH.sub.3 P(O)!.sub.1.5    ______________________________________    !}.sub.n

An esterification kettle is charged with the alcoholic componentdissolved in 250 ml of toluene, with 0.5 grams of pyridine. The mixtureis heated to reflux at about 110° C after which slow addition iscommenced of the two phosphorus components dissolved in 250 ml oftoluene. The reaction is continued until only a slight trace of chlorideis observed in the off-gas and in the supernatent liquid. The solventproduct is separated by decantation, filtration and washing. The productof n=10 degree of aggregation begins melting at 70° C, and when used inthe flame retardancy test, has an Oxygen Index of 23 when used at 10 wt.% based upon the total modified polymer, polyethylene terephthalate.

EXAMPLE 6

The use of a halogen substituted alcohol material as one of thecomponents is shown in the present example which employs the equationshown below:

    ______________________________________     (HOCH.sub.2).sub.3 CCH.sub.2 !.sub.2 O + 3 (HOCH.sub.2).sub.2 C(CH.sub.2    Cl).sub.2 ! +     ##STR13##    MW       254.3        173        167.4    moles    0.05         0.15       0.3    gms      12.7         26.0       50.22    1/n{ (OCH.sub.2).sub.3 CCH.sub.2 OCH.sub.2 (CH.sub.2 O).sub.3 !     (ClCH.sub.2).sub.2 C(CH.sub.2 O).sub.2 !.sub.3  ClCH.sub.12 P(O)!.sub.6    }.sub.n    ______________________________________

The two alcohols are charged into an esterification kettle with 250 mlof toluene as a solvent and 0.5 grams of pyridine. The reaction mixtureis heated to 110° C and slow addition started of the phosphorus acidiccomponent dissolved in 250 ml of toluene over a period of about 3 hours.The reaction is continued until hydrogen chloride evolution ceases,after which the solid product is removed. When admixed with polyethyleneterephthalate as a 10% additive by wt., the Oxygen Index is 24-24.5.

EXAMPLE 7

This example shows the preparation of a polymeric phosphorus ester,proceeding according to the equation below:

    ______________________________________     ##STR14##              2CH.sub.3 POBr.sub.2 +                         ##STR15##    MW       254         222         284    moles    0.1         0.2         0.1    gms      25.4        44.4        28.4    1/n { (OCH.sub.2).sub.3 CCH.sub.2 OCH.sub.2 C(CH.sub.2 O).sub.3 ! CH.sub.3     P(O)!.sub.2  C.sub.6 H.sub.5 P(O)!}.sub.n    ______________________________________

The dipentaerythritol is charged with 250 ml of toluene and 0.5 grams ofpyridine into a chemical reaction vessel and brought to 110° C. Afterbringing the reaction mixture to the reflux temperature, slow additionis commenced of the methyl phosphonic and phenylphosphonic dibromidesdissolved in 250 ml of toluene. The reaction is continued until hydrogenbromide evolution is negative. The hard colorless product is removedfrom the vessel and filtered and washed with toluene before being driedin a vacuum oven at 50° C. The product has a softening point of 80° C.The product is useful as a flame retardant.

EXAMPLE 8

The following Examples 8-14 follow the procedure of Example 1 assummarized below.

The equation and the reaction is as follows using 2% by wt. of picolineas a catalyst

    ______________________________________     ##STR16##    MW       254          153.4      212    moles    0.1          0.1        0.15    gms      25.4         30.6       31.8    1/n{ (OCH.sub.2).sub.3 CCH.sub.2 OCH.sub.2 C(CH.sub.2 O).sub.3 ! P(O)! BrC    H.sub.2 P(O)!.sub.1.5 }.sub.n    ______________________________________

The product with n about 20 is a white powder which begins melting at240° C, and does not support combustion.

EXAMPLE 9

The equation for the reaction is shown below, with 1% by wt. of calciumchloride as a catalyst

    ______________________________________     ##STR17##    MW       190.06       167.36     2.12    gms      38.0         25.1       3.18    moles     0.2         0.15       0.15    1/n{ BrCH.sub.2 C(CH.sub.2 O).sub.3 !.sub.2  ClCH.sub.2 P(O)!.sub.1.5     BrCH.sub.2 P(O)!.sub.1.5 }.sub.n    ______________________________________

The product has a melting point of 95° C and a degree of aggregation nof about 5.

EXAMPLE 10

The three component ester employs the reactants shown below:

    ______________________________________     ##STR18##    MW       136.15       120.15     153.4    moles    0.05         0.2        0.267    gms      6.81         24.08      40.2    1/n{ C(CH.sub.2 O).sub.4 !  CH.sub.3 C(CH.sub.2 O).sub.3 !.sub.4     P(O)!.sub.5.33 }.sub.n    ______________________________________

The hard white product of n about 15 has a melting point of 235° C anddoes not support combustion.

EXAMPLE 11

The preparation of a bromine containing phosphorus ester is shown in thepresent example which proceeds according to the equation shown below:

    ______________________________________     ##STR19##    MW       136.15       190.06     153.3    moles    0.1          0.067      0.2    gms      13.6         19.8       30.6    1/n{ C(CH.sub.2 O).sub.4 !  BrCH.sub.2 C(CH.sub.2 O).sub.3 !.sub.0.67     P(O)!.sub.2 }.sub.n    ______________________________________

The product begins to soften at 110° C. The Oxygen Index for 10% by wt.in admixture with polyethylene terephthalate is 26.

EXAMPLE 12

A phosphorus ester is prepared in accordance with the reaction shownbelow:

    ______________________________________     ##STR20##    Moles     0.2         0.133      0.4    gms      27.2         16.05      61.4    MW       136.15       120.15     153.4    l/n{ C(CH.sub.2 O).sub.4 !  CH.sub.3 C(CH.sub.2 O).sub.3 !.sub.0.67     P(O)!.sub.2 }.sub.n    ______________________________________

The white crystalline product has a melting point of 175° C and in aflame retardancy test with polyethylene terephthalate 10% by wt. has anOxygen Index of 26.

EXAMPLE 13

An ester based upon 2 alcohol components and an acid component isprepared according to the reaction shown in the example below:

    ______________________________________    4/5C(CH.sub.2 OH).sub.4 + 4/15CH.sub.3 C(CH.sub.2 OH).sub.3    + 1-1/3POCl.sub.3    MW        136.15      120.15      153.4    gms       31.8        8.4         53.7    moles     0.233       0.07        0.35    ______________________________________

to give a product of the composition, where n is about 80.

    ______________________________________    { C(CH.sub.2 O).sub.4 !.sub.0.8  CH.sub.3 C(CH.sub.2 O).sub.3 !.sub.0.27     P(O)!.sub.1.33 }.sub.n    Melting Point        Oxygen Index    ______________________________________    130° C        24    ______________________________________

EXAMPLE 14

The three components shown below are reacted as follows

    ______________________________________     ##STR21##    MW         153.4       133.0       136.15    gms        30.7        13.3        27.3    moles      0.2         0.1          0.2    ______________________________________

The composition of the product is

    { C(CH.sub.2 O).sub.4 !  CH.sub.3 P(O)!.sub.0.5  P(O)! }.sub.n ;

with n of about 30, the product does not support combustion.

    ______________________________________    Melting Point        Oxygen Index    ______________________________________    240° C        25    ______________________________________

EXAMPLE 15

This example shows trimethyl phosphite as an ester component on aphosphorus compound in the reaction below as a modification of Example1.

    ______________________________________    2 C(CH.sub.2 OH).sub.4 + 3(CH.sub.3).sub.2 C(CH.sub.2 OH).sub.2 +     ##STR22##    MW         136.15     104         124.08    gms        27.2       20.8        49.7    moles       0.2       0.3          0.4    l/n{ C(CH.sub.2 O).sub.4 !  (CH.sub.3).sub.2 C(CH.sub.2 O)!.sub.1.5     P!.sub.2 }.sub.n    ______________________________________

The product of n about 10 does not support combustion.

EXAMPLE 16

The three components shown below are reacted as follows.

    ______________________________________    3C(CH.sub.2 OH).sub.4 + 2 POCl.sub.3 + 3 CH.sub.3 POCl.sub.2 →    prod. + 12 HCl    MW         136.15     153.4       133.0    gms        40.8       30.7        39.9    moles       0.3       0.2         0.3    ______________________________________

The esterification is conducted as described in Example 1, with theexception that no catalyst is used. The reaction proves much slower,requiring about a tenfold reaction time to completion. The product is

    { C(CH.sub.2 O).sub.4 !.sub.3  P(O)!.sub.2  CH.sub.3 P(O)!.sub.3 }.sub.n

with n the degree of aggregation about 15.

    ______________________________________    Melting Point        Oxygen Index    ______________________________________    80                   23    ______________________________________

EXAMPLE 17

The use of a trivalent phosphorus compound is shown by the reaction ofthe three component system shown below:

    ______________________________________    C(CH.sub.2 OH).sub.4 + 4 CH.sub.3 C(CH.sub.2 OH).sub.3 + 51/3 PCl.sub.3    MW        136.15      120.15      137.4    moles     0.05        0.2         0.267    gms       6.81        24.08       36.69    ______________________________________

The reaction is conducted as described in Example 1 with the evolutionof 16 moles of HCl to give a product of the composition

    { C(CH.sub.2 O).sub.4 !  CH.sub.3 C(CH.sub.2 O).sub.3 !.sub.4  P!.sub.5.33 }.sub.n

with n about 50.

The product does not support combustion.

EXAMPLE 18

The three components shown below, including a tetrafunctional phosphorusreactant, bis(dichlorophosphonyl)methane

    ______________________________________    CH.sub.3 C(CH.sub.2 OH).sub.3 + 1/2 (CH.sub.3).sub.2 C(CH.sub.2 OH).sub.2    + Cl.sub.2 (O)PCH.sub.2 P(O)Cl.sub.2    MW        120.15      104         250    moles     0.1         0.05        0.1    gms       12.0        5.0         25.0    ______________________________________

are reacted as described in Example 1 to give a product

    { CH.sub.3 C(CH.sub.2 O).sub.3 !  (CH.sub.3).sub.2 C(CH.sub.2 O)!.sub.0.5  (O)PCH.sub.2 P(O)!}.sub.n,

with n about 20.

EXAMPLE 19

The three components shown below

    ______________________________________     ##STR23##                   2POCl.sub.3 +                             ClCH.sub.2 POCl.sub.3    MW       372.4       153.4       167.2    moles    0.1         0.2         0.1    gms      37.2        30.7        16.7    ______________________________________

are reacted as described in Example 1 to give a product of thecomposition

    { (OCH.sub.2).sub.3 CCH.sub.2 OCH.sub.2 C(CH.sub.2 O).sub.2 CH.sub.2 OCH.sub.2 C(CH.sub.2 O).sub.3 !  P(O)!.sub.2  ClCH.sub.2 P(O)!}.sub.n

with n about 2.

EXAMPLE 20

This example shows two sulfur compounds of phosphorus used with anoligomeric pentaerythritol starting material. The three components shownbelow

    ______________________________________     ##STR24##                   + 2PSCl.sub.3                             + 2CH.sub.3 PSCl.sub.2    MW       40.9        169.4       14.9    moles    0.1         0.2         0.2    gms      40.9        33.9        29.8    ______________________________________

are reacted as described in example 1 to give a product of thecomposition, with n about 50.

    { ((OCH.sub.2).sub.3 CCH.sub.2 OCH.sub.2).sub.3 CCH.sub.2 O!  P(S)!.sub.2  CH.sub.3 P(S)!.sub.3 }.sub.n

EXAMPLE 21

The three components shown below, including a monofunctional phosphorusreactant, dimethyl phosphinyl chloride,

    ______________________________________    C(CH.sub.2 OH).sub.4 + 2/3POCl.sub.3 + 2(CH.sub.3).sub.2 POCl    MW        136.2       153.4       112.5    moles     0.1         0.67        0.2    gms       13.6        10.2        22.5    ______________________________________

are reacted as described in Example 1 to give a product of thecomposition

    { C(CH.sub.2 O).sub.4 !  P(O)!.sub.0.67  (CH.sub.3).sub.2 P(O)!.sub.2 }.sub.n

with n, the degree of aggregation, about 5.

EXAMPLE 22

The three components shown below, including methyl phosphorusbis(dimethylamide) as an amide component

    ______________________________________    C(CH.sub.2 OH).sub.4 + 2/3CH.sub.3 C(CH.sub.2 OH).sub.3 + 3CH.sub.3    P(N(CH.sub.3).sub.2).sub.2    MW        136.2       120.2       134    moles     0.1         0.67        0.3    gms       13.6        8.0         40.2    ______________________________________

are reacted at 120°-150° until the stoichiometric amount ofdimethylamine has been evolved. The resulting product has thecomposition

    { C(CH.sub.2 O).sub.4 !  CH.sub.3 C(CH.sub.2 O).sub.3 !.sub.0.67  CH.sub.3 P!.sub.3 }.sub.n

with n of about 5. The product does not support combustion.

EXAMPLE 23

The present ternary ester composition have a definite melting range, sothat the ester can be added to a molten organic polymer such as ethyleneterephthalate or a nylon. In contrast the binary ester ofpentaerythritol and phosphoryl chloride, for example does not melt, andis therefore insoluble in the organic polymer. The ternary ester ofExample 4, based upon 1 mole of pentaerythritol, 1/6 mole of phosphorylchloride and 1.75 moles of methyl phosphonic dichloride has a meltingrange of 85° to about 150° C, so that the ternary ester is a usefuladditive flame retardant.

EXAMPLE 24

Another instance relative to the same binary ester as above, is theternary ester of Example 12 based upon 1 mole of pentaerythritol, 2/3mole of trimethylol ethane, and 2 moles of phosphoryl chloride. Thisternary ester has a melting range of 175°-230° C so that the stableflame-retardant additive readily melts with the organic polymer such asnylon 6,6.

What is claimed is:
 1. The combination of an organic polymer togetherwith 1-20 wt.% of a polymeric ester having as moieties thereof, (A) analiphatic alcoholic moiety of an alcoholic reactant of 5 to 20 carbonatoms, and from 2 to 6 hydroxyl functional groups, with the proviso thatthere is no hydrogen atom on the carbon atoms beta to the hydroxyloxygen, (B) a moiety of a phosphorus-containing acid halide, ester oramide reactant of 0 to 20 carbon atoms having from 1 to 4 functionalgroups, and (C) a different alcoholic moiety as defined in (A) or adifferent phosphorus-containing moiety defined in (B), the said esterhaving a degree of aggregation of 2 to 100, and with each of (A), (B)and (C) being present at from 1 mole to 99 mole %, with the proviso thatthe number of alcoholic functional groups on the alcoholic reactants isequal to the number of the said functional groups on thephosphorus-containing reactants.
 2. The combination of polyethyleneterephthalate together with 1-20 wt.% of a polymeric ester having asmoieties thereof, (A) an aliphatic alcoholic moiety of an alcoholicreactant of 5 to 20 carbon atoms, and from 2 to 6 hydroxyl functionalgroups, with the proviso hat there is no hydrogen atom on the carbonatoms beta to the hydroxyl oxygen, (B) a moiety of aphosphorus-containing acid halide, ester or amide reactant of 0 to 20carbon atoms having from 1 to 4 functional groups, and (C) a differentalcoholic moiety as defined in (A) or a different phosphorus-containingmoiety defined in (B), the said ester having a degree of aggregation of2 to 100, and with each of (A), (B) and (C) being present at from 1 moleto 99 mole %, with the proviso that the number of alcoholic functionalgroups on the alcoholic reactants is equal to the number of the saidfunctional groups on the phosphorus-containing reactants.